Gastroenteritis is a significant problem in animal husbandry as well as in human medicine. Gastroenteritis is primarily caused by food-borne pathogens, such as bacterial species belonging to the Salmonella, Campylobacter, Escherichia, Listeria, Clostridium, or Shigella geni, which typically ingress through the lower parts of the gastrointestinal tract. In animal husbandry, gastrointestinal infections can be relatively well controlled by inclusion of sub-therapeutic doses of antibiotics in the feed. However, the preventative use of antibiotics is either banned or strongly discouraged in many countries due to the growing emergence of antibiotic-resistant pathogens. Likewise, antibiotics in human medicine are nowadays subject to more strict use policies. Alternative treatments include the use of dietary supplements such as short or medium chain organic acids, manno-oligosaccharides which interfere with mucosal attachment of pathogens, or fructan-based oligosaccharides which stimulate beneficial gut microbiota. Inoculation of animals with competitive-exclusion microbiota is another form of treatment.
There is a need to extend the range of preventive and therapeutic treatment methods against gastrointestinal infections, especially since some of the proposed control agents do not yield consistent results. For instance inulin and oligofructose have been reported to decrease the incidence of systemic infection by Salmonella enterica serovar Typhimurium and Listeria monocytogenes in mice, whereas in rats it increased the levels of S. enterica ser. Enteritidis in the gut and promoted systemic translocation. Likewise, inclusion of a oligofructose from Jerusalem artichokes in chicken diet promoted colonisation of chicken caeca by Salmonella enterica ser. Typhimurium, whereas oligofructose from chicory roots had the opposite effect.
Arabinoxylans are polysaccharides that occur in the cell wall of most monocotyledonous plant species, and are therefore abundantly present in cereal-based diets. They comprise a main chain of β-1,4-linked D-xylopyranosyl units to which O-2 and/or O-3 □-L-arabino-furanosyl units are linked, together with minor substituents such a alpha-(methyl)glucuronyl, acetyl, feruoyl, and/or p-coumaryl groups. Arabino-oligosaccharides (hereinafter referred as AXOS), i.e. oligosaccharides derived by partial hydrolysis of arabinoxylan, have been demonstrated to stimulate the growth and improve the feed intake when added to the diet of animals (WO03/015533), whereas uncleaved arabinoxylan is well known to hamper efficient food utilisation. AXOS has also been shown to stimulate beneficial microflora in the caeco-colonic compartment of the gastrointestinal tract (WO06/002495), while arabinoxylan promotes fermentation in the ileum. The effect of dietary supplement with arabinoxylan on the attachment S. enterica ser. Enteritidis to the ileum of broiler chicks has been investigated. It was found that dietary addition of 0.5% arabinoxylan from corn hull (average molecular weight 500,000) slightly promoted Salmonella attachment when the chicks were raised at 23° C., whereas a slight decrease in attachment was observed in chicks raised at the suboptimal temperature of 29° C., although none of the effects were significant.